change=0.01
def dayup(up):
    n=1.0
    for i in range(365):
        if i%7 in [6,0]:
            n=n*(1-up)
        else:
            n=n*(1+up)
    return n
while(dayup(change)<37.78):
    change+=0.001
print("每天需要努力：{:.3f}".format(change))